Adjustable Crack Trainer using Vice Screw?

Having looked at a lot of crack trainer designs, I find myself wanting something that has a bit easier adjustability/compact design for living in cramped city housing. I had the thought that one option for fine tuned adjustability might be to use a vice screw, like this:

Has anyone done anything like this? I grew up doing carpentry as a job, but it's been so long and designing this to be stable and perform well is a bit outside of my pay grade by myself. Curious to source any thoughts before I try prototyping. 

How long/tall do you want your crack trainer? 

I know there'd be a way to rig it for something quite long, but for my purposes 5-6 feet would be plenty